In the field of radio communication, standardization of a communication standard called LTE (Long Term Evolution) and a communication standard called LTE-A (LTE-Advanced) based on LTE has been currently completed or considered in 3GPP (3rd Generation Partnership Project), in order to further improve a communication speed and communication capacity.
On the other hand, radio communication devices such as a smartphone are widely used. Such a radio communication device can use many radio communication schemes such as HSPA (High Speed Packet Access) and GSM (registered trademark) (Global System for Mobile communication), besides the radio communication scheme such as LTE, for example.
For example, the radio communication device can use many radio communication schemes by utilizing a software radio technology. The software radio is radio communication or a technology thereof capable of switching the radio communication scheme by changing control software without changing an electronic circuit (hardware), for example. The software radio can miniaturize the whole device without increasing the number of electronic circuits in the radio communication device, for example, and thus can also reduce costs.
Note that such switching of the radio communication scheme (or RAT (Radio Access Technology)) may be referred to as Inter-RAT (or inter-RAT handover) or the like, for example.
As to switching of the RAT, in the radio communication device, for example, whole radio control firmware related to the radio communication scheme after switching is loaded into a command memory (for example, IRAM (Intelligent RAM)) from a data memory (for example, DRAM (Dynamic Random Access Memory)). Then, the radio communication device uses the loaded whole radio control firmware or a part thereof to perform radio communication according to the radio communication scheme after switching.
In this case, as to the IRAM storing the radio control firmware after switching, for example, loading is performed after the IRAM is powered up again and rebooted, for example.
Therefore, when loading the whole radio control firmware related to the radio communication scheme after switching, for example, the IRAM is changed to a sleep state in the radio communication device, and then processing is performed, such as powering up the IRAM again.
As a technology related to the software radio, there is the following technology, for example.
The technology is provided with two modules: a basic module for realizing minimum software download using each communication system and an expansion module for realizing more sophisticated applications. The basic module is held normally and the expansion module is stored by communication using the basic module.
According to the technology described above, software download and management can be efficiently performed with smaller memory capacity, for example.
There is also a technology in which, when recognizing a reception condition or reception state such as a low power level of a received signal, a receiver transmits request information to a download center and receives optimum software corresponding to the request information from the download center to rewrite contents in a storage unit.
According to the technology described above, a software download system can be provided, which is capable of rewriting programs according to a communication status of the receiver, for example.
Furthermore, there is also a technology in which, after a communication device is turned on, algorithm 1 is downloaded to store channel capacity information in a storage unit, then algorithm 2 is downloaded to store channel capacity information in the storage unit, and the two channel capacities are compared to select any one of the algorithms.
According to the technology described above, one terminal system or radio unit is allowed to use many CDMA communication systems, for example, and an optimum radio system can be selected according to a communication situation.
Meanwhile, there is a technology called a memory overlay method. In the memory overlay method, when a program is difficult to be stored in a memory, for example, the program is divided into segment (module) files for each function, and the program itself manages and controls each of the segments.
As a technology related to the memory overlay method, there is the following technology, for example.
Specifically, there is a form editing device configured to edit a machine code for a page printer to create a machine code for a serial printer.
According to the technology described above, form overlay print can be performed in the serial printer, for example.
There is also an OS overlay method in which, when a corresponding input-output driver is yet to be loaded in case of an input-output request, a FIFO register stores to that effect, and after multiple interrupt is resolved, a management unit reads the FIFO register and the input-output driver is loaded and operated.
According to the technology described above, the OS can be operated in a small execution area using a normal disk driver, for example.
There is also an information output device including a memory configured to exclusively store at least overlay information and a synthesizing unit configured to read and synthesize information stored in an image memory and the overlay information, wherein the synthesizing unit overlaps the overlay information with the information stored in the image memory and outputs the information thus obtained.
According to the technology described above, an overlay method for the information output device can be provided, which can improve the processing speed, simplify the control of hardware, and economically handle output information such as image information and graphic information, for example.
Japanese Laid-open Patent Publication No. 2005-223788, Japanese Laid-open Patent Publication No. 2004-227173, Japanese Laid-open Patent Publication No. 2003-333663, Japanese Laid-open Patent Publication No. 03-227285, Japanese Laid-open Patent Publication No. 63-113739, Japanese Laid-open Patent Publication No. 60-42791 are examples of related art.